Entrainment of FCC from fluidized beds — A new correlation for the elutriation rate constants Ki∞*

Batch and continuous experiments of fluidization have been carried out in columns of diameter 76 and 152 mm. Gas velocities of 0.1–0.8 m/s were used with mixtures of coarse and fine FCC as the feed materials. The total entrainment flux EZ and the elutriation rate constants Ki∞* are found to depend on the gas velocity in the form of EZ ∝ Un and Ki∞* ∝ Um, respectively. The values of n and m depend on the bed compositions and particle size; they become smaller at higher gas velocities. For FCC, n has an average value of 4.0 in the velocity range 0.2–0.4 m/s and tends to a value of 2 at higher gas velocities. The effect of column diameter depends on the gas velocity profiles and is reduced for column diameters above 0.1 m. Empirical correlations to predict Ki∞* and EZ have been developed from the results.